AB21 Class A Amplifier Analog Lab Experiment Board Ver. 1.0 QUALITY POLICY To be a Global Provider of Innovative and Affordable Electronic Equipments for Technology Training by enhancing Customer Satisfaction based on Research, Modern manufacturing techniques and continuous improvement in Quality of the products and Services with active participation of employees. An ISO 9001: 2000 company 94-101, Electronic Complex, Pardesipura INDORE-452010, India. Tel.: 91-731-2570301 Fax: 91-731-2555643 Email: [email protected]Web: www.scientech.bz
Transcript
AB21 Class A Amplifier
Analog LabExperiment Board
Ver. 1.0
QUALITY POLICY
To be a Global Provider of Innovative and Affordable Electronic Equipments for Technology Training by enhancing Customer Satisfaction based on Research, Modern manufacturing techniques and continuous improvement in Quality of the products and Services with active participation of employees.
3.Experiment 7To study the operation of Class A Amplifier.
4.Datasheet 9
5.Warranty 11
6.List of Service Centers 11
7.List of Accessories with AB21 12
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AB21
INTRODUCTION
AB21 is a compact, ready to use Class A Amplifier experiment board. This is useful for students to understand the working and operation of various Voltage amplifier categories. It can be used as stand alone unit with external DC power supply or can be used with SCIENTECH ANALOG LAB ST2612 which has built in DC power supply, AC power supply, function generator, modulation generator, continuity tester, toggle switches, and potentiometer.
List of Boards :
Model Name
AB01 Diode characteristics (Si, Zener, LED)AB02 Transistor characteristics (CB NPN)AB03 Transistor characteristics (CB PNP)AB04 Transistor characteristics (CE NPN)AB05 Transistor characteristics (CE PNP)AB06 Transistor characteristics (CC NPN)AB07 Transistor characteristics (CC PNP)AB08 FET characteristicsAB09 Rectifier CircuitsAB10 Wheatstone BridgeAB11 Maxwell’s BridgeAB14 Darlington PairAB15 Common Emitter AmplifierAB16 Common Collector AmplifierAB17 Common Base AmplifierAB18 Cascode AmplifierAB19 RC-Coupled AmplifierAB20 Direct Coupled AmplifierAB22 Class B Amplifier (push pull emitter follower)AB23 Class C Tuned AmplifierAB25 Phase Locked Loop (FM Demodulator & Frequency
Divider / Multiplier)AB28 Multivibrator (Mono stable / Astable)AB29 F-V and V-F ConverterAB30 V-I and I-V ConverterAB31 Zener Voltage Regulator AB32 Transistor Series Voltage RegulatorAB33 Transistor Shunt Voltage Regulator
Differentiator)AB43 Operational Amplifier (Adder/Scalar)AB44 Operational Amplifier (Integrator/ Differentiator)AB45 Schmitt Trigger and ComparatorAB51 Active filters (Low Pass and High Pass)AB52 Active Band Pass Filter AB53 Notch Filter AB54 Tschebyscheff FilterAB56 Fiber Optic Analog LinkAB65 Phase Shift OscillatorAB66 Wien Bridge OscillatorsAB67 Colpitt OscillatorAB68 Hartley OscillatorAB80 RLC Series and RLC Parallel Resonance AB81 Kirchoff’s Laws (Kirchhoff’s Current Law & Kirchhoff’s
Voltage Law)AB82 Thevenin’s and Maximum power Transfer TheoremAB83 Reciprocity and Superposition TheoremAB84 Tellegen’s TheoremAB85 Norton’s theoremAB88 Diode ClipperAB89 Diode ClampersAB90 Two port network parameterAB91 Optical Transducer (Photovoltaic cell)AB92 Optical Transducer (Photoconductive cell/LDR)AB93 Optical Transducer (PhotoTransistor)AB96 Temperature Transducer (RTD & IC335)AB97 Temperature Transducer (Thermocouple)AB101 DSB Modulator and DemodulatorAB102 SSB Modulator and DemodulatorAB106 FM Modulator and Demodulator
………… and many more
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THEORY
The class A amplifiers are the amplifiers which deliver maximum undistorted symmetrical output voltage swing to the low impedance load. Generally any system (like a stereo, radio or television) consists of several stages of amplification. When the signal passes through these stages, the power level of signal rises so much that the later stages require high power handling circuit elements such as power transistors. Also as the load impedance of these later stages is very small (of the order of 8 ohm for stereo amplifier speakers), heavy collector current flows. To handle this, transistors heaving power rating of 1W or more are used in power amplifiers.
Power amplifiers are broadly classified as :
1. Class A (Voltage Amplifier)
2. Class B (Push-Pull Emitter Follower)
3. Class C Tuned Amplifier
Class A Amplifier :
Class A amplifier is basically a voltage amplifier in which transistor operates in active region for the entire cycle of input AC signal. In other words the collector current flows for 360° of AC signal
Fig. 1For class A amplifiers the Q point is located somewhere near the middle of the AC load line and thus offers maximum amplification of the input signal as shown below :
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Fig. 2
The collector current IC is non-zero even when the input signal is zero i.e. the IC flows for 100% of time. This leads to power dissipation even in quiescent condition.
EXPERIMENT
Objective :
To study the operation of Class A Amplifier.
Apparatus required :
1. Analog board of AB21.
2. Variable DC power supply +12V from external source or ST2612 Analog Lab.
3. Function Generator.
4. Oscilloscope.
Circuit diagram :
Circuit used to study the operation of Class A Amplifier is shown below :
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Fig. 3Procedure :
• Connect +12V variable DC power supplies at their indicated position from external source or ST2612 Analog Lab.
• Connect 1Vp-p AC signal (1KHz) at the Vin input of the AB21.
1. Connect Oscilloscope at the output terminals of AB21 and observe the output waveform.
2. Gradually increase the input signal up to the value before the signal just get clipped or decrease the DC supply voltage to the value before the signal just get clipped. This is the maximum amplification of Class A Amplifier AB21.
3. Calculate the peak-to-peak value of the output signal.ResultsInput ac signal amplitude (Vin) : ...................................Vp-p
Output ac signal amplitude (Vout) : ...................................Vp-p
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Voltage gain (A = Vout/Vin) : .................................
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DATASHEET
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WARRANTY
1) We guarantee the instrument against all manufacturing defects during 24 months from the date of sale by us or through our dealers.
2) The guarantee covers manufacturing defects in respect of indigenous components and material limited to the warranty extended to us by the original manufacturer, and defect will be rectified as far as lies within our control.
3) The guarantee will become INVALID.
a)If the instrument is not operated as per instruction given in the instruction manual.
b)If the agreed payment terms and other conditions of sale are not followed.
c) If the customer resells the instrument to another party.d)Provided no attempt have been made to service and modify the
instrument.
4) The non-working of the instrument is to be communicated to us immediately giving full details of the complaints and defects noticed specifically mentioning the type and sr. no. of the instrument, date of purchase etc.
5) The repair work will be carried out, provided the instrument is dispatched securely packed and insured with the railways. To and fro charges will be to the account of the customer.
DESPATCH PROCEDURE FOR SERVICE
Should it become necessary to send back the instrument to factory please observe the following procedure:
1) Before dispatching the instrument please write to us giving full details of the fault noticed.
2) After receipt of your letter our repairs dept. will advise you whether it is necessary to send the instrument back to us for repairs or the adjustment is possible in your premises.
Dispatch the instrument (only on the receipt of our advice) securely packed in original packing duly insured and freight paid along with accessories and a copy of the details noticed to us at our factory address.
